Spring-jack wedge



UNITED STATES PATENT OFFICE.

HOMER ANDERSON, OF PEEKSKILL, NEW YORK.

SPRING-JACK WEDGE.

SPECIFICATION forming part of Letters Patent No. 338,131, dated March 16, 1886.

Application filed August 12, 1885. Serial No. 174,196.

To all whom it may concern:

Be it known that I, HOMER ANDERSON, a citizen of the United States, residing at Peekskill, in the county of Westchester and State of New York, have invented certain useful Improvements in Spring Jack NVedges, of which the following is a specification.

My invention relates to plugs and pins used in electric switch-boards, and those particularly which are called wedges, and are used for changing and for diverting without interrupting electric currents. Some features of my invention are applicable to all kinds of such plugs, pins, and wedges.

The objects of my invention are, first, to reduce the tendency to the breaking of attached conducting-cords; second, to obviate the necessity for winding the handles of wedges with silk or other insulating-thread, for the purpose of firmly connecting the cord and wedge and of insulating the connections; third, to afford a simple and quick means of attaching cords to the wedges, and, fourth, to attach the conducting-plates to the body of the wedge in such manner as to make a thin and light wedge without impairing its strength. My means of accomplishing these objects will be found fully set forth in the following specification and the accompanying drawings, in which Figure 1 is an edge view of the old form of wedge with the insulating-wrapping of the handle removed, and showing the method of attaching the conducting-plates to the body of the wedge. Fig. 2 is a top View of the same in its finished form. Fig. 3 shows how in pushing the wedge into a spring-jack the conducting-cord is bent, resulting in its speedy breaking. Fig. 4 is a top view of my form of wedge, partly in section. Fig.5 is an edge view of the same, also partly in section. Fig. 6 is a top view of a similar wedge, showing a different method of attaching the conductingcord from that shown in Fig. 4. This is also partly in section. Fig. 7 is an edge View of my form of wedge, showing the position the conducting-cord assumes when the wedge is being inserted in place. Fig. 8 shows a top View of my wedge with still another method of attaching conducting-cords; Fig. 9 is a cross-section through S of Fig. 4; and Fig. 10 is aview of the tip end of my wedge, showing (No model.)

Similar letters refer to similar parts throughp out the several views.

Referring to Fig. 1, let a b 0 represent the body of a wedge made of vulcanized rubberor any suitable non-conducting material that may be similarly molded to this shape. a is sheathed on top and bottom with brass or like conducting material in thin plates, as a a, which are secured in place by screws or screwrivets, as 1 1, which are so inserted as to avoid all metallic contact between the two plates. Each of these plates is extended over the edge of a, and along the body of the wedge (indicated by b) to a hole, 4., which hole is continued through the handle 0, being enlarged at the outer end to receive the conducting-cord c. This extension (shown) marked 2 is a continuation of the top plate. The bottom plate is extended in precisely the same manner on the opposite edge of the wedge. The extension 2 is usually channeled, as at 6. e c, Fig. 2, represents conducting-cords, one connecting with each plate, and at a few inches from c the cords are united into one strand. The insulation around these cords is removed from their ends, and the bared wire is drawn through c by the hole 4, and being laid in the channel 6 silk or linen thread is firmly wound around the whole, binding the cords in contact with the plates, and giving to the wedge the appearance,when finished, as shown in Figs. 2 and 3.

Ininserting these wedges between the springs ofa jack pressure is applied by the thumb against 0 with a result to the cord as shown in Fig. 3. This short bending of thecord causes the wire within to break, requiring the substitution of a new cord, which, it is obvious, is a troublesome as well as an expensive operation.

In using these wedges three or four, one upon the other, are commonly used in one jack, and as the method of attaching plates a involves a thickness of three-eighths of an inch, the accumulation of wedges not only puts a great strain upon the springs of the jack, but also makes a bulky pile of wedges that is not infrequently the cause of mishaps. Sometimes the whole number will be ejected from their place; or in withdrawing a single wedge much care is required to avoid displacing all of them.

In the construction of my wedge I first prepare the plates a a by plowing dovetailed grooves longitudinally in the surfaces that are to adhere to the body a. One form of dovetailing is shown in Figs. 9 and 10. Fig. 9 is a cross-section through Fig. 4 at s, and Fig. 10 is a view of the tip end of a wedge. Several grooves may be made in the plates,instead of one wide one, as here shown, or thinner metal may be used and have the edges turned under to form the groove. Avariety of methods may be resorted to to see-ure the effect of the dovetailing; but I have found this form of groove simple, cheap, and very effective. I next provide a mold to give me just the form of the entire wedge. Then, placing one of the plates to in the mold, the mold is filled with the body material in aplastic state. The second plate a is placed upon the body material, the plunger ofthe mold is pressed home, a vulcanizing heat is applied to the mold, and a wedge-blank is the result having the metallic plates secured to the body without screws or rivets, and is ready for the operations of drilling, polishing, and attaching the cords.

Another method I have employed with success is this: Instead of using rubber in a plastic or unvulcanizcd state for filling the mold, I use that which has been vulcanized, cutting it from rods or sheets of a proper thickness. Blanks for the purpose may be punched from sheets, the rubber being heated to a condition of softness to facilitate punching. \Vhen a blank and the grooved plates are inserted in the mold, pressure and a certain degree of heat are applied, the heat being just sufficient to impart a semi-plastic condition to the rubber. The result is a wedge-blank not differing materially from that made by the first process described. This process has several advantages to recommend it. As a general thing, vulcanized rubber is more easily proeurable than the unvulcanized, and this process may often be made use of in a very simple manner. I have adapted a mold to a common vise, and used the vise as a press, heating the mold to the proper degree in a forge or other fire, and applying the pressure gradually as the mold imparted its heat to the rubber.

It has been observed that the old form of wedge, as in Fig. 1, comprises the sheathed part a, the insulated body I), and the handle 0.

Referring to Figs. 4, 5, 6, 7, and 8, it will be seen that my wedge comprises the addition of a projection, d, from the handle 0, and its use is made apparent by reference to Fig. 7. Fig. 3 shows how conducting-cords are injured by the application of thumb-pressure, and in Fig. 7 is shown how, in the use of my wedge, the pressure is against (1, while the cord 6 assumes a natural curve, and is thereby rendered man y times more durable than by the old method. This projection d, or modifications of it, may be applied to the old form of wedge without materially altering its general appearance.

In constructing new wedges the projection preferably is a part of the wedge; or it may be affixed to old or new wedges as a separate attachment.

I exhibit three new methods of attaching the conducting-cords to the wedges. The old method of attachment, as in Fig. 1, may be applied to any of my wedges, or any of my methods of attachment are applicable to the wedge shown in Fig. 1.

Referring to Fig. 4, the upper side of the wedge shows a cord attached,while the lower side is without the cord. Holes are drilled through the handle 0, into which small metallic tubes 10 are closely fitted. To the inner ends of these tubes wires 01. are attached,which extend through longitudinal holes in b to chambers k, which are mortised in the edge of body a close to the plate a,with which this wire is to be connected. lVithin the chambers 7c each wire is soldered or otherwise secured in contact to its respective plate a. The outer ends of the holes made in c to receive the small tubes are countersunk, as shown at 8, and a cove is channeled in projection d, as at 7. The ob ject of the countersink and cove combined is to receive the sheath 1'' of the tip of the cord 0. Now, to attach an ordinary flexible cord to this wedge it is only necessary to cut the tips J to a certain or equal length, and as theylie naturally side by side, bend the tips J with their points slightly toward each other. Then inserting tips J in, the tubes 10, a little pressure will cause the sheaths i to fall within the recesses provided for them. In use the pulling upon the cord is usually parallel with the wedge,and as considerable outward pressure is required to release the sheath z from its seat its release is not likely to occur in actual practice. 'When desirable to insulate the sheaths i, it may be done bypassing a piece of rubber tubing over them; or the sheaths may be made of celluloid, rubber, or other non-conductor.

In Fig. 6 I show a simple'manner 01" attachment. Holes are drilled through c and d, as in Fig. 4; but no tubes are inserted, and no countersinks are used, nor covesin the extension (I. The sheathsi are removed from the ends of the cord 6, and a wire is attached directly to the tips J; or the said tips may be removed and a wire, 12, be connected, as at 5, directly with the spiral e,which runs through the cord 6. The leading-wire 12 may be so connected with the wire in any conducting-cord, or the wire of the cord may itself be extended as a leading-wire, as convenience may permit. So connected the wire at is drawn through 0, pulling after it the end of the insulated cord into the enlarged hole in a. Wire n is then secured to its appropriate plate a, as at 1, in the chamber 7c, and the finished wedge presents the appearence on its edge, asshown in Fig. 7.

Fig. 8 is given the shape of Fig. 2,with the addition of projection d. Plates a have extensions 3 on the sides instead of the edges, as in Fig. 1. These extensions are channeled,

as at 6, and the wire from the cords is joined thereto through hole 4, and the whole is then wound with the insulation, as in Fig. 2.

The plates a a may be made to adhere to the rubber without dovetailing, but I prefer to give them a positive fastening.

These wedges may be supplied to the trade in the form of blanks consisting of the body and adhering conducting-plates, and manufacturers may attach cords and finish the wedges to suit their own fancy or particular uses. Of course the dovetailed plates may be attached to blanks by ordinary mechanical methods of fitting; but the vulcanizing and rubber-softening processes described are so much more expeditious and less costly as to be the far more preferable means.

Having described my invention, what I claim and desire to secure by Letters Patent, is-- 1. A spring-jack wedge of the form herein shown, consisting of an insulating-handle, to which the conducting-plates are made to adhere by means of a dovetailed joint, substantially as and in the manner described.

2. A spring-jack wedge of the form herein shown, comprising an insulating -handle, to

which conducting-plates are made to adhere by means of a dovetailed joint, substantially as and in the manner described, and a projection, substantially as shown, from said handle between the points to which the conductingcords are joined, substantially as and for the purpose set forth.

3. A spring jack wedge of the description shown, consisting of an insulating-handle, to which conducting-plates are made to adhere by means of a dovetailed joint, substantially as set forth, in which the conducting-plates and conducting-cords are connected by means of conductors buried in the body of the handle, and from which an extension, substantially as shown, projects between the points to which the conducting-cords are attached, said extension having a length sufficient to protect said cords from injury by finger-pressure, as herein set forth.

4. A spring -jack wedge of the class described, provided with a projection, d, from the handle 0 between the points for attaching the cords c, the united width of said projection (I and the said cords e 0 being uniform, or nearly so, in width with said handle 0, substantially as illustrated and described.

5. A spring-jack wedge of the form described, having conducting-plates a, joined to conducting-cords c by means 'of conductors secured to plates a within recesses provided for the purpose, embedded in the body I) and handle 0, as and for the purpose set forth.

6. In a spring-jack wedge of the form herein shown, the combination of plates a a, conductors 12, joined thereto and buried in the body I) and handle 0, and connected with conducting-cords e e, and extension (1, substantially as shown, having a thickness adapted to this form of wedge and a length sufficient to protect the cords e e from finger-pressure,

substantially as set forth.

7. In a spring-jack wedge, the combination of conducting-plates a a, conducting-wires a n joined thereto, buried in the body I), and attached to tubes l0 10 in handle 0, recess 8 in c, conducting-corde, sheathi and tip J, and

extension (I, provided with recess 7, substanbody between the points to which conductingcords are to be attached, said projection having a thickness adapted to this form of wedge and a length sufficient to protect the cords from finger-pressure, all substantially as set forth.

9. A wedge or plug for electrical switch= boards, provided with contact-tubes 10,recesses 8 and 7, adapted to be used with detachable conductingcords, substantially as set forth.

10. A wedge or plug for electrical switch- V boards, provided with tubes 10, recesses 8 and 7, and conductors n, to be used in combination with detachable cords having tip-sheaths t, made of a non-conducting substance, for the purpose herein specified.

11. A wedge or plug for electrical switchboards, provided with recesses 8 and 7, tubes 10, and conductors n, to be used in combination with detachable conductingcords having I metallic tip-sheaths t, and a tube of rubber or other non-conducting wrapping made to inclose said tips about projection d for the purpose of insulation, as set forth.

12. A wedge for electrical switchboards of the class described, in which the conducting-cords are attached on each side of a projection from the handle, the united widths of the said projection and cords being nearly uniform with the width of said handle, said cords being connected with the conductingplates of the wedge by means of conductors embedded in the body of the wedge, as set forth.

Signed at Peekskill, in the county of Vestchester and State of New York.

HOMER ANDERSON.

Vitnesses:

0. WV. HORTON, WM. DUNPHY.

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